CHAPTER IV 
ORES OF PLATINUM 
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Pratinym—Quariries AND Distrisurion—Platinum (Pt. 
at. wt., 195; sp. gr., 21-5; melting-point, 3200° F.) was 
Named from its resemblance to silver (diminutive of Spanish- 
Plata). It is exceptionally heavy, and owing to its high 
melting-point and resistance to most acids and oxidation, is 
of special value in many chemical, electrical, and industrial 
Processes, and for jewelry. Platinum owing to its scarcity 
and unique qualities, is now the most expensive of ordinarily 
used metals ; its price has risen from 8s. an oz. in 1870 and 
£3 an oz. in 1900, to £25 per oz., or five times the value of 
gold. Platinum has been found in the nickel-iron meteorites, 
and, being one of the heavy metals and associated with deep- 
Seated igneous rocks, is probably a constituent of the nickel 
fon core of the earth. It has been widely regarded as an 
Igneous mineral, and as a primary constituent of ultra-basic 
rocks, In many cases it is of hydrothermal origin, and even 
0 ultra-basic rocks is sometimes a secondary constituent. 
Platinum, though scarce in quantity, is widely distributed ; 
Most of its occurrences are where basic igneous rocks have 
been raised to the surface by mountain-forming uplifts, 
and usually those of the Altaid System. Its only British 
Occurrences are in Southern Ireland and Cornwall, It has 
been found in most European countries. Russia has been 
the main producer, and yielded in 1914 over QO per cent. 
of the world's supply. Platinum occurs in Burma, Central 
Asia, ang Japan. In North America it has been found in 
any places among the Western Mountains, and along the 
Appalachian Mountains, while Sudbury in Canada supplies 
Most of jtg only important compound, sperrylite (PtAsp). 
0uth America was its original home. In South Africa it 
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